84 Lumber said yesterday that it had closed nine stores as a result of consolidations in six markets, but none in the Pittsburgh area. In January, the Washington County building materials company reported an $820 million drop in 2007 sales. And last year, it announced more than one round of job cuts at its headquarters in Eighty Four and closed stores as it braced for a lingering housing slowdown.

AK Steel Holding Corp. said yesterday that it would increase spot market prices for its carbon steel products by $50 per ton for all new orders, effective immediately. AK Steel said the price increase comes with increased demand for the products, as well as higher costs for materials. AK Steel shares rose $1.90, or 3.7 percent, to $53.38 yesterday.

The Justice Department yesterday approved Sirius Satellite Radio Inc.'s proposed $5 billion buyout of rival XM Satellite Radio Holdings Inc., saying the deal was unlikely to hurt competition or consumers. The deal still requires approval from the Federal Communications Commission, which prohibited a merger when it first granted satellite radio operating licenses in 1997.

A restaurant and a specialty grocery store signed leases to occupy a new Strip District building this spring. Cioppino Seafood.Chophouse.Bar and Right by Nature Natural Foods Market will be located across the street from the Cork Factory Lofts at 2349 Railroad Street.

Tiffany & Co., which plans to open a local store at Ross Park Mall in the fall, yesterday said its fourth-quarter earnings fell almost 16 percent, hurt by one-time charges, but its adjusted results beat analyst expectations. Tiffany earned $118.3 million, or 89 cents per share, in the quarter ended Jan. 31, down from $140.5 million, or $1.02 per share, a year ago. Excluding one-time charges, profit was $1.27 per share, above the $1.21 analysts surveyed by Thomson Financial expected. Its shares climbed 10.49 percent yesterday.

PNC Financial Services Group said it entered into an agreement with Columbus, Ohio-based Nationwide Bank to provide back-office and customer service functions for the bank's direct loan products, including home equity installment loans and lines of credit and vehicle secured loans ... PPG Industries volunteered to participate in a U.S. Environmental Protection Agency program that will assess the use of nanoscale materials in chemicals production.